The present invention relates to enclosures for industrial lasers and, more particularly, to a variety of passive, light-tight sealing arrangements for preventing the escape of harmful laser radiation from an enclosed chamber.
Industrial lasers are commonly used for purposes of cutting and welding. U.S. and international standards have been developed and divide all industrial lasers into four major hazard categories, i.e., four broad classes (I to IV). Laser enclosures are commonly used as protective enclosures for higher powered lasers, e.g., Class II, Class III or Class IV lasers, and allow the higher powered lasers to operate in a lower classification. For example, some Class I industrial lasers consist of a higher class laser enclosed in a properly interlocked and labeled protective enclosure.
A number of conventional laser enclosures utilize active sealing arrangements including one or more motive elements that must be actively controlled or positioned. As such, active laser enclosures are complex, costly to produce, and introduce a substantial limitation on processing efficiency, especially where successive workpieces are to be processed. In addition, a number of conventional laser enclosures incorporate passive sealing arrangements. However, these conventional passive laser enclosures often utilize complex, cumbersome, and difficult to manufacture components. Accordingly, there is a need for an improved laser enclosure which achieves sealing without requiring active drive devices or complex movable sealing members.
This need is met by the laser enclosure of the present invention. The laser enclosure comprises an enclosed laser chamber which may, for example, encase a Class IV laser to allow it to operate as a Class I laser. With reference to the several embodiments of the present invention described herein, by xe2x80x9clight-tightxe2x80x9d we mean to reduce the amount of laser light that escapes from the laser enclosure to a level that is below allowable safety standard thresholds.
In accordance with a first embodiment of the present invention, a laser enclosure is provided comprising an enclosed laser chamber, a load/un-load region, and a partition for preventing the passage of laser light from the enclosed laser chamber to the load/un-load region. The partition is positioned between the enclosed laser chamber and the load/un-load region. The partition includes a stationary partition and a rotary partition. The stationary partition includes an upper stationary partition edge and a lower stationary partition edge. The rotary partition includes a central rotary partition axis, at least one pair of opposing workpiece supports, and an upper and lower rotary partition edge.
The laser enclosure further comprises a rotary partition drive, an upper partition interface formed between the upper rotary partition edge and the upper stationary partition edge, and a lower partition interface formed between the lower rotary partition edge and the lower stationary partition edge. A light-tight sealing region formed at a selected one of the upper partition interface and the lower partition interface is configured to seal the selected partition interface from the passage of laser light. The light-tight sealing region includes a curved stationary passage wall, a curved rotary passage wall, a space between the curved stationary passage wall and the curved rotary passage wall. The space between the curved stationary passage wall and the curved rotary passage wall defines an arcuate passage.
The light-tight sealing region can further define an upper and a lower light-tight sealing region formed at the upper and the lower partition interface, respectively, configured to seal the lower and upper partition interfaces from the passage of laser light. The upper and lower light-tight sealing regions include a curved upper and lower stationary passage wall, a curved upper and lower rotary passage wall, and a space between the curved upper and lower stationary passage wall and the curved upper and lower rotary passage wall. The space between the curved upper and lower stationary passage wall and the curved upper and lower rotary passage wall defines an upper and a lower arcuate passage.
When the rotary partition is substantially perpendicular with the floor the arcuate passage forms a light-tight seal at the selected partition interface. The arcuate passage is configured so that laser light entering the arcuate passage undergoes at least three scattering or dispersive reflections along the length of the arcuate passage.
The curved stationary passage wall and the curved rotary passage wall can include a coating. The coating can comprise a carbon black paint or other composition that optimizes the absorption, scattering or dispersion of incident laser light.
The laser enclosure can further include a sidewall light-tight partition configured to prevent the passage of laser light across a sidewall of the rotary partition.
The laser enclosure can further comprise a scrap conveyor assembly which includes a scrap conveyor and a scrap chute. A scrap removal brush is secured to the rotary partition and sweeps along the curved stationary passage wall as the rotary partition is rotated about the central rotary partition axis. The scrap chute is configured to direct scrap to the scrap conveyor and the scrap conveyor is configured to carry the scrap to a scrap depository.
The laser enclosure can further comprise one or more robotic lasers mounted on a robotic laser platform and positioned within the enclosed laser chamber. The rotary partition has a loading face which faces in the direction of the load/un-load region and a processing face which faces in the direction of the enclosed laser chamber. The at least one pair of opposing workpiece supports can be positioned on the loading face of the rotary partition, on the processing face of the rotary partition, or on both the loading face and the processing face of the rotary partition. At least one workpiece can be positioned and secured between the at least one pair of opposing workpiece supports. The rotary partition drive is configured to impart rotary motion to the rotary partition about the central rotary partition axis to rotate the rotary partition 180 degrees about the axis and transport the at least one workpiece between the load/un-load region and the enclosed laser chamber. The rotary partition can be reciprocated 180 degrees to move the at least one workpiece to and from the load/un-load region and the enclosed laser chamber. The rotary partition drive or an additional rotary support drive assembly is configured to impart rotary motion to the at least one pair of opposing workpiece supports to rotate the at least one workpiece about a workpiece axis.
In accordance with another embodiment of the present invention, the light-tight sealing region includes a longitudinal, T-shaped ridge and a longitudinal, T-shaped partition flap. The longitudinal, T-shaped partition flap extends across the length of the stationary partition, and the longitudinal, T-shaped ridge extends across the length of the rotary partition. The light-tight sealing region can further define an upper and a lower light-tight sealing region at the upper and the lower partition interfaces, respectively, configured to seal the upper and lower partition interfaces from the passage of laser light. The upper and lower light-tight sealing regions include a longitudinal, T-shaped ridge and a longitudinal, T-shaped partition flap.
The longitudinal, T-shaped partition flap can be a rigid plate connected to the stationary partition via a hinge or a flexible flap fixed to the stationary partition. When the rotary partition is substantially perpendicular with the floor, the longitudinal, T-shaped partition flap forms a light-tight seal at the selected partition interface when disposed against or interlocked with the longitudinal, T-shaped ridge. The longitudinal, T-shaped partition flap moves freely away from the longitudinal, T-shaped ridge when the rotary partition rotates about the central rotary partition axis. In the lower light-tight sealing region, the longitudinal, T-shaped partition flap is forcibly urged to an upright position against or interlocked with the longitudinal, T-shaped ridge.
The laser enclosure of this embodiment of the present invention can further include a sidewall light-tight partition configured to prevent the passage of laser light across a sidewall of the rotary partition.
In accordance with still another embodiment of the present invention, the light-tight sealing region includes a shallow longitudinal channel and a longitudinal partition flap. The longitudinal partition flap extends across the length of the stationary partition and the shallow longitudinal channel extends across the length of the rotary partition. The light-tight sealing region can further define an upper and a lower light-tight sealing region at the upper and the lower partition interfaces, respectively, configured to seal the upper and lower partition interfaces from the passage of laser light. The upper and lower light-tight sealing regions include a shallow longitudinal channel and a longitudinal partition flap.
The longitudinal partition flap can be a rigid plate connected to the stationary partition via a hinge or a flexible flap fixed to the stationary partition. When the rotary partition is substantially perpendicular with the floor, the longitudinal partition flap forms a light-tight seal at the selected partition interface when disposed within the shallow longitudinal channel. The longitudinal partition flap moves freely out of the shallow longitudinal channel when the rotary partition rotates about the central rotary partition axis. The longitudinal partition flap can be substantially vertical such that the longitudinal partition flap is equally spaced between a pair of walls of the shallow longitudinal channel, disposed within the shallow longitudinal channel in an orientation which is slightly off-center, or disposed within the shallow longitudinal channel in an orientation which is substantially diagonal such that the longitudinal partition flap contacts one of the walls of the shallow longitudinal channel. In the lower light-tight sealing region, the longitudinal partition flap is forcibly urged to an upright position within the shallow longitudinal channel.
The laser enclosure of this embodiment of the present invention can further include a sidewall light-tight partition configured to prevent the passage of laser light across a sidewall of the rotary partition.
In accordance with still another embodiment of the present invention, the light-tight sealing region includes a longitudinal ridge and a longitudinal partition flap. The longitudinal partition flap extends across the length of the stationary partition and the longitudinal ridge extends across the length of the rotary partition. The light-tight sealing region can further define an upper and a lower light-tight sealing region at the upper and the lower partition interfaces, respectively, configured to seal the upper and lower partition interfaces from the passage of laser light. The upper and lower light-tight sealing regions include a longitudinal ridge and a longitudinal partition flap.
The longitudinal partition flap can be a rigid plate connected to the stationary partition via a hinge or a flexible flap fixed to the stationary partition. The longitudinal partition flap can include at least one additional protruding member configured to seal the selected partition interface from the passage of laser light. When the rotary partition is substantially perpendicular with the floor, the longitudinal partition flap forms a light-tight seal at the selected partition interface when disposed against the longitudinal ridge. The longitudinal partition flap moves freely away from the longitudinal ridge when the rotary partition rotates about the central rotary partition axis. In the lower light-tight sealing region, the longitudinal partition flap is forcibly urged to an upright position against the longitudinal ridge.
The laser enclosure of this embodiment of the present invention can further include a sidewall light-tight partition configured to prevent the passage of laser light across a sidewall of the rotary partition.
In still another embodiment of the present invention, the light-tight sealing region includes a pair of longitudinal ridges and a longitudinal partition flap. The longitudinal partition flap extends across the length of the stationary partition and the pair of longitudinal ridges extend across the length of the rotary partition. The longitudinal partition flap can be a rigid plate connected to the stationary partition via a hinge or a flexible flap fixed to the stationary partition.
The light-tight sealing region can further define an upper and a lower light-tight sealing region at the upper and the lower partition interfaces, respectively, configured to seal the upper and lower partition interfaces from the passage of laser light. The upper and lower light-tight sealing regions include a pair of longitudinal ridges and a longitudinal partition flap.
When the rotary partition is substantially perpendicular with the floor, the longitudinal partition flap forms a light-tight seal at the selected partition interface when disposed between the pair of longitudinal ridges. The longitudinal partition flap moves freely out of the space defined between the pair of longitudinal ridges when the rotary partition rotates about the central rotary partition axis. The longitudinal partition flap can be disposed between the pair of longitudinal ridges in an orientation which is slightly off-center, substantially diagonal such that the longitudinal partition flap contacts one of the pair of longitudinal ridges, or substantially vertical such that the longitudinal partition flap is equally spaced between the pair of longitudinal ridges. In the lower light-tight sealing region, the longitudinal partition flap is forcibly urged to an upright position between the pair of longitudinal ridges.
The laser enclosure of this embodiment of the present invention can further include a sidewall light-tight partition configured to prevent the passage of laser light across a sidewall of the rotary partition.
Accordingly, it is an object of the present invention to provide an improved laser enclosure which provides a light-tight seal at a partition interface and which optimized the absorption, scattering or dispersion of incident laser light. These and other objects and advantages of the present invention will be apparent from the following description, the accompanying drawings, and the appended claims.